Gas heater



July 27, 1948. E. G. PETERSON ErAL GAS HEATER 2 Sheets-Sheet 1 Filed Oct. 5. 1944 Mm QW ww .www

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ORNEY July 27 1948 E. G. PETERSON .ETAL 2,446,059

GAS HEATER Filed 0G12. 5, 1944 2 Sheets-Sheet 2 BY l , I f ORNEY Patented July 27, 1948 GAS HEATER.

Erie G. Peterson, New York, and David P. Graham, Westbury, N. Y Enginee assignors to Peabody ring Corporation, New York, N. Y., a corporation of New York application october s, im, sensi No. 551,263

11 claim. (ci. zes- 49) This invention relates to heat exchangers and more particularly to heaters for heating nuids under pressures up to several atmospheres, and

has fori an object to provide a iluid heater of the above type having novel and improved details of construction and features of operation.

In accordance with the present invention we provide an all metal fluid heater having novel and improved means for protecting both the outer and inner shells against the high temperatures. In one embodiment the heater is provided with one or more concentric passages within the outer shell through which the gases to be heated pass. A corrugated spacing member is disposed in each passage to form a plurality of separated axial channels for the gases. The spacing memberv strengthens the assembly and also provides an internal shield to prevent direct radiation of heat from the inner wail to the outer wall of each concentric passage. It also greatly increases the surface area for heat transfer from the metal to the gases. These combined effects prevent either the exterior shell or interior shell from reaching too high a temperature, and e1iminate the need for a refractory liner,

The invention is particularly applicable to gas heaters of the type used for heating air or other combustion supporting gases for catalytic cracking processes or for the operation of gas turbines. Such heaters vinclude a burner firing into a combustion chamber and passages to supply gases to be heated in heat exchange relation thereto for preheating and to discharge the gases into the combustion chamber to be mixed with products of combustion for final heating. If the heater is to be used for heating air or other combustion supporting gases a portion thereof may be supplied to the burner to support combustion. An adjustable member, such as a bame, may be provided to control the amount of gas which passes directly into the burner to support combustion and the amount which passes through the preheating passages for subsequent mixture with the products of combustion.

The invention also provides for maintaining uniform combustion across the combustion chamf ber area and for regulating the temperature distribution thereacross. In one embodiment the burner includes an air register having peripheral air doors provided with individual adjusting means for controlling theair distribution.

Although the novelfeatures which are believed to be characteristic of this invention are pointed out more particularly in the claims appended hereto, the invention will be better understood by 2 referring to the4 following description, taken in connection with the accompanying drawings in which specific embodiments thereof have been set forth for purposes of illustration.

In the drawings:

Fig. 1 is a longitudinal section taken on the line I-I of Fig. 2 showing a gas heater embodying the present invention;

Fig. 2 is a transverse section taken on the line 2-2 of Fig. 1;

Fig. 3 is a broken longitudinal section through a gas heater illustrating a further embodiment of the invention; and

Fig. 4 is a partial transverse section taken on the line 4 4 of Fig. 3.

Referring to the drawings more in detail, the heater is shown in Fig. 1 as comprising an outer cylindrical pressure resisting shell I0 secured to a head ring Il which is attached by means of bolts I2 to a flange Il formed on a fuel burner register front plate Il.

The front plate Il carries an air register l5 of standard type having a plurality of peripheral air doors Il through which air is admitted for combustion to a throat piece i1 which is shown as attached to the register I5 and as flaring outwardly and terminating in a radial flange IB around which auxiliary air for combustion and cooling flows in a manner to be described. The throat piece I1 is shown as provided with holes lla through which air is supplied to the interior of the throat piece for cooling purposes and for controlling combustion. The doors i 8 are shown as regulated simultaneously by a handle 20 which is attached to one of the doors i6. Suitable links Ila connect the doors for operation in unison.

The air register l5 is shown as attached to an inner plate 22 which is provided with a flange 2l by which it is attached to the ilangeil of the front plate I4 and is spaced from the front plate to receive suitable heat insulation 24 therebetween. l h

An atomizer 30 for atomizing pulverized, liquid or gaseous fuel extends through the front plate Il axially of the furnace and is provided with a tip Il from which the atomized fuel is ejected for combustion. The atomizer 30 may be of standard construction. for example. that shown in the Fisher Patent 1,326,488, dated December 80, 1919. The atomizer includes a diffuser 32 which is positioned to cooperate with the burner throat I1 for directing the spray of fuel as required to obtain efficient combustion. An igniter II may also be provided. The air doors I6 admit air for combustion around the entire periphery of the burner throat and: cause the same to rotate as it advance.h between the diffuser 32 and the throat |1 to be mixed with the fuel for combustion.

A metal liner 35 is separated from the shell I6 to provide an annular air passage 36 therebetween and is positioned relative to the shell I6 by a corrugated spacing member 31 which extends around the entire periphery of the shell to separate the passage 36 into a plurality of independent channels as indicated at Fig. 2.

A second concentric passage 46 is formed by a plurality of units 46a. consisting of concentric rings 4I and 42 and corrugated spacing members 43 similar to the corrugated spacing member 31 above mentioned which space the rings to provide the air passage 46 therebetween. The units are of a size to be inserted within the liner 35 and to be carried thereby. The rings 4| constitute the side wall of the combustion chamber. In the embodiment shown in Fig. 1 a plurality of such units are disposed along the combustion chamber. The rings 4| of the various units are made progressively of increased diameter so that each ring 4I is oset with respect to the preceding ring 4I to provide an air passage 44 therebetween through which a portion of the air from the passage 46 enters the combustion chamber. The spacing members 31 increase the heat transfer to the gases and with the liner 35 serve to center and suppor the units 46a. If the units 46a are not required to be self-contained the rings 42 may be omitted andthe spacing member attached directly to the liner 35.

Suitable vanes may be provided for directing the air which passes through the annular passages 44. Inthe embodiment shown an axial vane 45 is attached to the wall 4| of thesecond unit and extends parallel to the wall 4| of the next succeeding unit to cause the air which enters the combustion chamber through the corresponding passage 44 to flow along the periphery of the chamber.

A conical shaped vane 46 is shown as attached to the wall 4| of the :fourth unit in a position to direct the air which passes through the preceding passage 44 radially toward the axisof the chamber.

It is to be understood 'that similar vanes may be attached to the various units so as to cooperate with each of the passages 44 and may be arranged to direct the air as desired either radially toward the axis of the chamber or axially along the periphery thereof.

The walls 4| of the successive units are offset so that passages 46 are of decreasing area suited to maintain Aa uniform velocity of air as the quantity f air is reduced due to the introduction of progressive amounts into the combustion chamber through the passages 44.

It is to be understood that the passages 46 may be built up of any desired number of units and that the units may be all of the same .size if desired. The units may be made segmental if desired to facilitate assembly and removal. The inner shell 4| may be solid omitting passages 44 if desired.

A ring 56 attached to the ring 4| of the Vfirst unit forms a chamber '5I communicating with both the passage 36y and the passagef46 and arranged to cause the air or gases which are passed through the passage 36 in a direction toward the burner end of the yheater to reverse and flow through the passages 46 to the opposite ends of the heater. The chamber 5I also is open to an -and is adjusted by rods 54 which are shown as attached by universal joints 66 to the baille 63 and which extend through the head ring I| and flange I3 and are provided with actuating handles 56. The rods 54 are threaded through bosses 61 attached to the head ring Il so that they are advanced axially by rotation of the handle 56. When in closed position the baille 63 engages the ring 56 to close the chamber 6I and prevent passage of air into the air register chamber 62. Air from the air register chamber 62 also passes into the combustion chamber between the ring 56 and the flange I6 of the burner throat. Consequently,

controlled quantities of air are admitted at various axially spaced zones along the combustion chamber. A ring 56 is shown as provided at the burner throat for supplying gaseous or pulverlzed fuel when desired from a supply pipe (not shown). The exit end of the heater is formed by a conical section 66 of the shell I6 having a flange 6I which is secured by bolts 62 to a flange 63 carried by a duct 64. An air supply duct 65 extends through the conical section 66 into registration with a conical passage 66, formed between the conical section 66 and an inner conical member 66. The passage 66 is closed at one end by a cylindrical liner 69 and is open at the other end to the passage 36. Suitable heat insulation 16 is provided around the conical section 66 of the pressure shell I6. The final passage 46 opens into the combustion chamber near the zone of the conical liner 66. The duct 66 is provided with a flange 1I for attachment to a supply pipe not shown.

Operation In the operation of this device, air or other gases to be heated are passed through the duct 65 into the chamber 66; thence through the passage 36 to the chamber 6I at the burner end of the heater; thence through the various passages 46 from which successive portions of the air are withdrawn through the annular passages 44 and are supplied to the combustion chamber f'or mixing with the combustion gases. the remainder issuing from the open end of the flnal passage 46 at the discharge end of the combustion chamber. A controlled portion of the gases from the passage 36 enters the air register chamber 62 and passes through the air register doors and through the burner throat i1. The hot products of combustion pass through the duct 64 at the exit end of t-he combustion chamber and may be supplied for utilization to any desired piece of equipment such as a, catalyst chamber or a gas turbine.

The gases, in passing through the passage 66. are preheated and in passing through the return passages 46 are further heated lbefore they are supplied to the combustion gases. The portion of the gases which enter the combustion vchamber around the burner throat and through the successive passages 44 serve to control the combustion and the temperature of the combustion gases as they pass along the combustion chamber and also absorb heat from the combustion gases and thereby protect the inner walls 4| from the intense heat of combustion.

As above pointed out, the corrugated spacing s members l1 and u increase the area available for heat transfer by convection to the gases passing through the corresponding passages and also prevent direct passage of heat by radiation from the inner walls Il to the outer wall 4! of the 10 inner passage and from the inner wall 36 to the shell il of the outer passage. In this way it is possible to maintain the shell ill and walls Il at a suiflciently low temperature without the use of a refractory lining. At the same time the corrugated members 31 and I3 position the assembly'.

The above described furnace has been found to operate emciently and to be well suited for commercial operation wherein high pressures and m high rate of heat transfer to the gases is required. The inner rings Il may be corrugated if desired instead of smooth as shown so as to increase the area available for heat transfer.

Referring now to Fig. 3, a modified form of heater is shown which is the same general construction as the heater shown in Figs. 1 and 2 above described. To avoid repeating the de- .o

scription the corresponding parts have been given the same reference characters. In the embodi-y, ment of Fig. 3, however, a separate cooling me-"ila dium is passed through the outer passage '30 and the air to be heated is introduced in the burner u end of the shell and makes only a single passage along the combustion chamber. In this embodiment the burner end of the passage Il is closed by a ring III and a duct Bi communicates therewith to receive the fluid which has entered through the duct 6i and is passed along the passage 1l for cooling the outer shell I0.

A duct I5 communicates with both the air register chamber l2 and the passage M. The air supply to the chamber 52 and the passage 4l is 45 controlled by division plate It and an adjustable damper 81 attached thereto the position of which may be varied to control the relative amounts of air supplied to the two sides of the division plate II. 50

The outer passage lt is formed by a liner Illa and hner separated by a corrugated spacing member 31 as above described, and the inner passages are formed by units 40a provided with the corrugated spacing members It as above 55 member to the exhaust duct Il. In Fig. 3 the 65 air doors i6 are provided with individual control handles 20 which permit adjustment of the air distribution around the burners. These doors may be adjusted to obtain uniform temperature across the entire combustion chamber.

In this embodiment liquids or gases other than combustion supporting gases may be passed through the outer passage 3i. The construction and operation are otherwise similar to that of the embodiments shown in Figs. 1 and Zand described above.

It is to be noted that the cartridge construction including the corrugated spacing members is applicable to an unilred heat exchanger omitting the burner and combustion chamber, to promote heat transfer between fluids in the respective adjacent passages.

Although specific embodiments of the invention have been shown for purposes of illustration, it is to be understood that various changes and modifications may be made therein as will be apparent to a person skilled in the art. The invention is only to be restricted in accordance with the scope o1' the following claims.

What is claimed is: v

l. A heat exchanger comprising a closed shell, an inner liner spaced from said shell to form an annular fluid passage, a corrugated spacing member in said passage supporting said inner liner and dividing said annular passage into a plurality of separate axial channels, a second concentric liner disposed within said first inner liner and separated therefrom by a corrugated separator to form a second set of axial channels, and means supplying fluid to one of said passages, means connecting said passages for the series flow of said fluid therein and means discharging the fluid from the other of said passages.

2. A gas heater comprising a closed shell forming a combustion chamber, a burner within said shell, said burner including fuel admission means and an air register to supply air for combustion, an inner liner spaced from said shell to form an annular fluid passage, a corrugated spacing member in said passage supporting said inner liner and dividing said annular passage into a plurality of separate axial channels, a second concentric liner disposed within said rst inner liner and separated therefrom by a corrugated separator to form a second set of axial channels, an inlet duct supplying fluid to said first channels, means causing said fluid to flow serially through the two sets of passages and means discharging the fluid from said second passages into the combustion chamber for mixing with the combustion gases.

3. A gas heater comprising a closed shell forming a combustion chamber, a burner within said shell, said burner including fuel admission means and an air register to supply air for combustion, an inner liner spaced from said shell to form an annular fluid passage, a corrugated spacing member in said passage supporting said inner liner and dividing said annular passage into a plurality of separate axial channels, a second concentric liner disposed within said first inner liner and separated therefrom by a corrugated separator to form a second set of axial channels, an inlet duct supplying fluid to said first channels, means causing said fluid to flow serially through the two sets of passages and means discharging the fluid from said second passages into the combustion chamber for mixing with the combustion gases, and means supplying .a portion of the fluid from said channels to said air register for combustion.

4. A gas heater comprising a closed shell forming a combustionv chamber, a burner within said shell, said burner including fuel admission means and an air register to supply air for combustion, an inner liner spaced from said shell to form an annular fluid passage, a corrugated spacing member in said passage supporting said inner liner and dividing said annular passage into a plurality of separate axial channels, a second concentric liner disposed within said first inner liner and separated therefrom by a corrugated separator to form a second set oi' axial channels. an inlet duct supplying iluid to said first channels, means causing said uid to ilow serially through the two sets o! passages and means discharging the iluid i'rom said second passage into the combustion chamber for mixing with the combustion gases. means supplying a portion oi the iluid from said channels to said air register for combustion, and adjustable means controlling the relative quantity thus supplied to the air register.

5. A gas heater comprising a closed shell forming a combustion chamber, a burner within said shell, an inner liner spaced from said shell to form an annular gas passage, a corrugated spaclng member in said passage and dividing said annular passage into a plurality oi' separate axial channels, a second concentric liner separated by a corrugated separator from said ilrst liner and disposed within said nrst inner liner to form a second set of axial channels unconnected with the ilrst channels, an inlet duct supplying gas to said ilrst channels, means supplying other gas to said second channels, and means discharging the gas from said second channels into the combustion chamber for mixing with the combustion gases.

6. A fluid heater comprising a closed shell forming a combustlonchamber having a discharge opening at one end, a burner within said shell at the other end, said burner including fuel admission means and an air register to supply air for combustion, an inner liner spaced from said shell to form an annular iiuid passage extending from the zone of the burner to the zone of said discharge opening. a corrugated spacing member in said passage supporting said inner liner and dividing said annular passage into a plurality of separate axial channels, a second concentric liner separated by a corrugated spacing member from said liner and disposed within said ilrst inner liner to form a second set of axial channels unconnected with the first set. an inlet duct supplying uid to said first channels, an outlet duct communicating with said ilrst channels, a second inlet duct connected to supply air for heating to said second channels, and means supplying a portion of said air from said last duct to said air register for combustion.

7. A iluid heater comprising a closed shell forming a combustion chamber having a discharge opening at one end, a burner within said shell at the other end, said burner including fuel admission means and an air register to supply air for combustion, an inner liner spaced from said shell to form an annular fluid passage extending from the zone of the burner to the zone of said discharge opening, a corrugated spacing member in said passage supporting said inner liner and dividing said annular passage into a plurality of separate axial channels, a second concentric liner separated by a corrugated spacing member and spaced from said first liner and disposed within said rst inner liner to form a second set of axial channels unconnected to the first set of channels. an inlet duct supplying iiuid to said ilrstgchannels. an outlet duct communicating with vsaid irst channels, a. second inlet duct connected to supply air for heating to said second channels. means supplying a portion oi' said air from said last duct to said air register for combustion, and adjustable means controlling said portion.

8. A heat exchanger comprising a shell having a combustion chamber with a discharge opening at one end, a burner within said shell at the other end, said burner including i'uel admission means and an air register having adjustable peripheral doors to supply air for combustion and to cause same to "rotate, an inner liner spaced from lsaidshell to form an annular iluid passage, other concentric liners disposed vwithin said ilrst inner liner to form additional iluid passages, an inlet duct supplying iluid to said first passage, an outlet duct communicating with said first passage, a second inlet duct connected to supply air to said heat exchanger, means supplying a portion of said air from said last duct to said other passages for heating and means supplying another portion of said air from said last duct to said air register for combustion, and adjustable means controlling the relative values of said portions.

9. A gas heater comprising a closed shell, a burner within said shell, said burner including i'uel admission means and an air register having peripheral air inlet means to supply air for combustion and to cause the air to rotate, an inner metal liner forming a combustion chamber and spaced from said shell to form an annular air passage therebetween, a longitudinally corrugated spacing member in said passage supporting said liner and dividing said annular passage into' a plurality of separate axial channels, an air connection supplying air to the air register end oi said passage, discharge means to discharge said air from said passage into the combustion chamber to mix with the products of combustion, a duct supplying a portion of said air from said air connection to said air register for combustion, and adjustable means controlling the relative quantity of said air supplied to said air register and said passage.

10. A gas heater comprising a closed shell, a burner within said shell, said burner including fuel admission means and an air register having peripheral air inlet means to supply air for combustion and to cause the air to rotate, an inner metal liner forming a combustion chamber and spaced from said shell to form an annular air passage therebetween, a longitudinally corrugated spacing member in said passage supporting said liner and dividing said annular passage into a plurality of separate axial channels. an air connection supplying air to the air register end of said shell, a transverse division plate in said shell in registry with said air connection to form separate air ducts communicating respectively with said air register and with said axial channels, and means to adjust the relative quantities of air supplied to said separate ducts.

11. A gas heater comprising a closed shell, a burner lwithin said shell, said burner including fuel admission means and an air register having peripheral air inlet means to supply air for combustion and to cause the air to rotate, an inner metal liner forming a combustion chamber and spaced from said shell to form an annular air passage therebetween, a longitudinally corrugated spacing member in said passage supporting said liner and dividing said annular passage into a plurality of separate axial channels, an air conncction supplying air to the air register end of said shell, a transverse division plate in said shell in registry with said air connection to form separate air ducts communicating respectively with said air register and with said axial channels, and an adjustable vane on said division plate to adjust the relative quantities of air supplied to said separate air ducts.

ERIC G. PETERSON. DAVID P. GRAHAM.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date Blake May 13, 1930 Number 

